1. Polygons Mixed Exercise
Pg 132 – 133
Exercise 6h
No. 1 to No. 6

2. 1. Find the size of each marked Angle
Sum of exterior angles = 360°
110°+ 130°= 240°
m = 360°- 240°= 120° 2
p = 180°- 120°= 60° 1

3. Sum of exterior angles = 360° One interior angle = 180°- 30°= 150°
2. Find the size of each exterior angle of a regular polygon with 12 sides. What is the size of each interior angle?
Sum of exterior angles = 360°
360°÷ 12 = 30° 1
Interior + Exterior = 180°
One interior angle = 180°- 30°= 150° 1

4. 3. Find the size of the angle marked x°
Sum of interior angles = (5-2) x 180°
Sum of interior angles = 3 x 180°= 540° 1
90°+ 130° + 120° + 80° = 420°
x = 540°- 420°= 120° 2
Pentagon  5 sides

5. One exterior angle = 180° - 168°= 12°
4. How many sides has a regular polygon if each interior angle is 168°?
Interior + Exterior = 180°
One exterior angle = 180° - 168°= 12° 1
12°x n = 360°??
n = 360° ÷ 12° = 30 SIDES! 2

6. n = 360° ÷ 45°= 8 SIDES (OCTAGON)
5. Is it possible for each exterior angle in a regular polygon to be a) 45° b)75°
a) 45° x n = 360°???
n = 360° ÷ 45°= 8 SIDES (OCTAGON) 2
b) 75° x n = 360°???
n = 360° ÷ 75°= 4.8 (not possible!) 2

7. 6. Find the size of the marked angle
Sum of interior angles = (4-2) x 180°
Sum of interior angles = 2 x 180°= 360° 1
120° + 80°+ 80° = 280°
360°- 280°= 80° 2
Quadrilateral  4 sides
X = 180° – 80° = 100° 1
1 Mark for your presentation of working: Is it good? (1), Is it okay but could be better (0.5), Do you think you could have done much better? (0)

8. Polygons Plenary Quiz